University Of Tasmania

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Reduced resistance to sediment-trapping turfs with decline of native kelp and establishment of an exotic kelp

journal contribution
posted on 2023-05-19, 22:33 authored by Reeves, SE, Kriegisch, N, Craig JohnsonCraig Johnson, Scott LingScott Ling

Understanding the strength and type of interactions among species is vital to anticipate how ecosystems will respond to ongoing anthropogenic stressors. Here, we examine the ecological function of native (Ecklonia radiata) and invasive (Undaria pinnatifida) kelps in resisting shifts to sediment-trapping turf on reefs within the highly urbanized temperate Port Phillip Bay (PPB), Australia. Short-term (30 days) and long-term (232 days) manipulations demonstrated that kelp laminae can clear and maintain the substratum free of turfs, while conversely, removal of kelp leads to a proliferation of turfs. Analyses looking at the relationship between total length of E. radiata and U. pinnatifida and the area cleared of turf algae showed that the clearing effect of E. radiata over a year was greater than that of U. pinnatifida due to the annual die-back of the invasive. A natural experiment (608 days) identified that ongoing sea urchin (Heliocidaris erythrogramma) grazing led to native kelp bed decline, facilitating turf dominance. Even though U. pinnatifida establishes once native beds are disturbed, its ecological function in clearing turf is weaker than E. radiata, given its annual habit. In PPB, turfs represent the more persistent and problematic algal group and are likely changing the structure, function, and energy flows of shallow temperate reefs in this urbanised embayment.


Publication title











Institute for Marine and Antarctic Studies



Place of publication

175 Fifth Ave, New York, USA, Ny, 10010

Rights statement

Copyright 2018 Springer-Verlag GmbH Germany, part of Springer Nature

Repository Status

  • Restricted

Socio-economic Objectives

Control of pests, diseases and exotic species in marine environments; Marine biodiversity